Methods for treating cancer are largely classified into surgical treatment, chemotherapy, and radiation therapy. In general, these treatments and therapies are used in combination depending on the type and progression of the cancer. These diverse and complex chemotherapeutic treatments work on not only cancer cells, but also normal cells, causing several side effects. In addition, there is a problem that the treatment efficiency may be reduced by obtaining the resistance of cancer cells to anticancer agents or the radiation resistance. Therefore, there is an urgent demand for the development of radiation sensitive enhancers and anticancer agents capable of minimizing side effects while enhancing effects of chemotherapy.
Meanwhile, several miRNAs are specifically expression during tumor formation and metastasis, and have been found to act as tumor genes or tumor inhibitor when the expression of each of a variety of target genes is controlled. In addition, the expression pattern of specific miRNAs between normal tissues and cancer tissues has increased the possibility of miRNAs as predictive markers in the treatment of cancer. To date, it has been reported that 2588 mature miRNAs are found in humans (miRBase release 21), but many miRNA functions are not yet known. Therefore, targeting new human miRNA libraries that continue to discover, there is a growing need for research to identify and characterize candidate miRNAs that are more efficacious for enhancing anticancer and radiation sensitivity.